1 3445 142 HYPERMETHYLATION OF ITGA4, TFPI2 AND VIMENTIN PROMOTERS IS INCREASED IN INFLAMED COLON TISSUE: PUTATIVE RISK MARKERS FOR COLITIS-ASSOCIATED CANCER. PURPOSE: EPIGENETIC SILENCING OF TUMOR SUPPRESSOR GENES IS INVOLVED IN EARLY TRANSFORMING EVENTS AND HAS A HIGH IMPACT ON COLORECTAL CARCINOGENESIS. LIKEWISE, COLON CANCERS THAT DERIVE FROM CHRONICALLY INFLAMED BOWEL DISEASES FREQUENTLY EXHIBIT EPIGENETIC CHANGES. BUT THERE IS LITTLE DATA ABOUT EPIGENETIC ABERRATIONS CAUSING COLORECTAL CANCER IN CHRONICALLY INFLAMED TISSUE. THE AIM OF THE PRESENT STUDY WAS TO EVALUATE THE ABERRANT GAIN OF METHYLATION IN THE GENE PROMOTERS OF VIM, TFPI2 AND ITGA4 AS PUTATIVE EARLY MARKERS IN THE DEVELOPMENT FROM INFLAMED TISSUE VIA PRECANCEROUS LESIONS TOWARD COLORECTAL CANCER. METHODS: INITIAL SCREENING OF DIFFERENT CANCER CELL LINES BY USING METHYLATION-SPECIFIC PCR REVEALED A PUTATIVE COLON CANCER-SPECIFIC METHYLATION PATTERN. ADDITIONALLY, A DEMETHYLATION ASSAY WAS PERFORMED TO INVESTIGATE THE METHYLATION-DEPENDENT GENE SILENCING OF ITGA4. THE CANDIDATE MARKERS WERE ANALYZED IN COLONIC TISSUE SPECIMENS FROM PATIENTS WITH COLORECTAL CANCER (N = 15), ADENOMAS (N = 76), SERRATED LESIONS (N = 13), CHRONIC INFLAMMATION (N = 10) AND NORMAL MUCOSAL SAMPLES (N = 9). RESULTS: A HIGH METHYLATION FREQUENCY OF VIM (55.6 %) WAS OBSERVED IN NORMAL COLON TISSUE, WHEREAS ITGA4 AND TFPI2 WERE COMPLETELY UNMETHYLATED IN CONTROLS. A SIGNIFICANT GAIN OF METHYLATION FREQUENCY WITH PROGRESSION OF DISEASE AS WELL AS AN AGE-DEPENDENT EFFECT WAS DETECTABLE FOR TFPI2. ITGA4 METHYLATION FREQUENCY WAS HIGH IN PRECANCEROUS AND CANCEROUS TISSUES AS WELL AS IN INFLAMMATORY BOWEL DISEASES (IBD). CONCLUSION: THE ALREADY ESTABLISHED METHYLATION MARKER VIM DOES NOT PERMIT A SPECIFIC AND SENSITIVE DISCRIMINATION OF HEALTHY AND NEOPLASTIC TISSUE. THE METHYLATION MARKERS ITGA4 AND TFPI2 SEEM TO BE SUITABLE RISK MARKERS FOR INFLAMMATION-ASSOCIATED COLON CANCER. 2015 2 5435 43 RELATIVE ROLE OF METHYLATOR AND TUMOR SUPPRESSOR PATHWAYS IN ULCERATIVE COLITIS-ASSOCIATED COLON CANCER. BACKGROUND: CHRONIC ULCERATIVE COLITIS (UC) IS ASSOCIATED WITH AN INCREASED COLORECTAL CANCER RISK WHICH MAY BE SECONDARY TO REPETITIVE MUCOSAL INJURY. BOTH EPIGENETIC METHYLATION AND THE CLASSIC ADENOMA-TO-CARCINOMA SEQUENCE HAVE BEEN IMPLICATED IN THIS MALIGNANT TRANSFORMATION, BUT THE UNDERLYING MOLECULAR MECHANISMS REMAIN POORLY DEFINED. THIS STUDY COMPARES THE MOLECULAR CHARACTERISTICS OF COLITIS-ASSOCIATED AND COMMON COLORECTAL CANCERS. METHODS: NINETEEN PATIENTS WITH COLORECTAL ADENOCARCINOMAS ARISING WITHIN UC WERE MATCHED FOR AGE AND CANCER SITE WITH 54 PATIENTS WITH SPORADIC ADENOCARCINOMAS. TUMOR TISSUE WAS EXAMINED FOR BRAF MUTATIONS, CPG ISLAND METHYLATOR PHENOTYPE (CIMP), AND MLH1 PROMOTER METHYLATION. MUTATIONS OF KRAS AND P53 WERE ASSESSED BY SEQUENCING. RESULTS: PATIENT DEMOGRAPHICS WERE SIMILAR FOR THE TWO GROUPS. CIMP WAS OBSERVED IN 22% OF SPORADIC COLORECTAL CANCERS AND IN 5% OF UC CANCERS (P = 0.162). RATES OF BRAF MUTATION (4% VS 5%, P = 1.0), MLH1 METHYLATION (9% VERSUS 5%, P = 0.682), AND KRAS MUTATIONS (24% VERSUS 32%, P = 0.552) WERE SIMILAR BETWEEN THE GROUPS. HOWEVER, COLITIS-ASSOCIATED COLORECTAL CANCERS WERE MORE LIKELY TO HAVE A P53 MUTATION COMPARED TO SPORADIC ADENOCARCINOMAS (95% VERSUS 53%, P = 0.001). THE DOMINANT MUTATION FOR COLITIS-ASSOCIATED CANCERS WAS A MUTATION IN CODON 4, REPRESENTING HALF OF THE MUTATIONS. FURTHERMORE, COLITIS-ASSOCIATED CANCERS HAD A HIGHER RATE OF MUTATION IN CODON 8 (48% VERSUS 6%, P < 0.001) THAN SPORADIC COUNTERPARTS. CONCLUSIONS: UNLIKE OTHER INFLAMMATORY GASTROINTESTINAL CANCERS, COLITIS-ASSOCIATED COLORECTAL CANCERS DO NOT PREFERENTIALLY ARISE VIA A METHYLATOR PATHWAY WHEN COMPARED TO SPORADIC COLORECTAL CANCERS. CHROMOSOMAL INSTABILITY REMAINS AN IMPORTANT ETIOLOGY, BUT WITH A UNIQUE P53 FREQUENCY AND MUTATION PATTERN. 2011 3 780 51 CELL-FREE DNA PROMOTER HYPERMETHYLATION IN PLASMA AS A DIAGNOSTIC MARKER FOR PANCREATIC ADENOCARCINOMA. BACKGROUND: PANCREATIC CANCER HAS A 5-YEAR SURVIVAL RATE OF ONLY 5-7%. DIFFICULTIES IN DETECTING PANCREATIC CANCER AT EARLY STAGES RESULTS IN THE HIGH MORTALITY AND SUBSTANTIATES THE NEED FOR ADDITIONAL DIAGNOSTIC TOOLS. SURGERY IS THE ONLY CURATIVE TREATMENT AND UNFORTUNATELY ONLY POSSIBLE IN LOCALIZED TUMOURS. A DIAGNOSTIC BIOMARKER FOR PANCREATIC CANCER WILL HAVE A MAJOR IMPACT ON PATIENT SURVIVAL BY FACILITATING EARLY DETECTION AND THE POSSIBILITY FOR CURATIVE TREATMENT. DNA PROMOTER HYPERMETHYLATION IS A MECHANISM OF EARLY CARCINOGENESIS, WHICH CAN CAUSE INACTIVATION OF TUMOUR SUPPRESSOR GENES. THE AIM OF THIS STUDY WAS TO EXAMINE PROMOTER HYPERMETHYLATION IN A PANEL OF SELECTED GENES FROM CELL-FREE DNA, AS A DIAGNOSTIC MARKER FOR PANCREATIC ADENOCARCINOMA. METHODS: PATIENTS WITH SUSPECTED OR BIOPSY-VERIFIED PANCREATIC CANCER WERE INCLUDED PROSPECTIVELY AND CONSECUTIVELY. PATIENTS WITH CHRONIC/ACUTE PANCREATITIS WERE INCLUDED AS ADDITIONAL BENIGN CONTROL GROUPS. BASED ON AN OPTIMIZED ACCELERATED BISULFITE TREATMENT PROTOCOL, METHYLATION-SPECIFIC PCR OF A 28 GENE PANEL WAS PERFORMED ON PLASMA SAMPLES. A DIAGNOSTIC PREDICTION MODEL WAS DEVELOPED BY MULTIVARIABLE LOGISTIC REGRESSION ANALYSIS USING BACKWARD STEPWISE ELIMINATION. RESULTS: PATIENTS WITH PANCREATIC ADENOCARCINOMA (N = 95), CHRONIC PANCREATITIS (N = 97) AND ACUTE PANCREATITIS (N = 59) AND PATIENTS SCREENED, BUT NEGATIVE FOR PANCREATIC ADENOCARCINOMA (N = 27), WERE INCLUDED. THE DIFFERENCE IN MEAN NUMBER OF METHYLATED GENES IN THE CANCER GROUP (8.41 (95% CI 7.62-9.20)) VS THE TOTAL CONTROL GROUP (4.74 (95% CI 4.40-5.08)) WAS HIGHLY SIGNIFICANT (P < 0.001). A DIAGNOSTIC PREDICTION MODEL (AGE >65, BMP3, RASSF1A, BNC1, MESTV2, TFPI2, APC, SFRP1 AND SFRP2) HAD AN AREA UNDER THE CURVE OF 0.86 (SENSITIVITY 76%, SPECIFICITY 83%). THE MODEL PERFORMANCE WAS INDEPENDENT OF CANCER STAGE. CONCLUSIONS: CELL-FREE DNA PROMOTER HYPERMETHYLATION HAS THE POTENTIAL TO BE A DIAGNOSTIC MARKER FOR PANCREATIC ADENOCARCINOMA AND DIFFERENTIATE BETWEEN MALIGNANT AND BENIGN PANCREATIC DISEASE. THIS STUDY BRINGS US CLOSER TO A CLINICAL USEFUL DIAGNOSTIC MARKER FOR PANCREATIC CANCER, WHICH IS URGENTLY NEEDED. EXTERNAL VALIDATION IS, HOWEVER, REQUIRED BEFORE THE TEST CAN BE APPLIED IN THE CLINIC. TRIAL REGISTRATION: CLINICALTRIALS.GOV, NCT02079363. 2016 4 2071 42 EPIGENETIC CONTROL OF THE E-CADHERIN GENE (CDH1) BY CPG METHYLATION IN COLECTOMY SAMPLES OF PATIENTS WITH ULCERATIVE COLITIS. E-CADHERIN BELONGS TO THE CADHERIN FAMILY OF CALCIUM-DEPENDENT CELL-ADHESION MOLECULES. THE CADHERINS PLAY AN ESSENTIAL ROLE IN BIOLOGICAL PROCESSES SUCH AS ORDERING OF CELL SORTING, MIGRATION, AND DIFFERENTIATION, AND THEIR MALFUNCTIONING IS CONNECTED WITH NEOPLASIA. NEOPLASTIC PROGRESSION IN PATIENTS WITH CHRONIC ULCERATIVE COLITIS IS CHARACTERIZED BY THE DEVELOPMENT OF EPITHELIAL DYSPLASIA. TRANSCRIPTIONAL SILENCING OF TUMOR-SUPPRESSOR GENES BY PROMOTER METHYLATION HAS BEEN OBSERVED IN DIFFERENT TYPES OF HUMAN CANCERS AND DYSPLASIA. TO EXPLORE THE MODE OF E-CADHERIN REGULATION, 156 BIOPSY SAMPLES FROM 26 PATIENTS WITH LONG-STANDING ULCERATIVE COLITIS WERE SCREENED. TO DETECT THE METHYLATION STATUS OF OUR SAMPLES, A METHYLATION-SPECIFIC PCR WAS APPLIED. METHYLATION OF THE E-CADHERIN (CDH1) PROMOTER WAS DETECTED IN 93% OF THE PATIENTS WITH DYSPLASTIC BIOPSY SAMPLES, IN CONTRAST TO ONLY 6% OF THE PATIENTS WITHOUT DYSPLASIA (P < 0.001). WE ALSO EXAMINED THE LEVEL OF SYNTHESIS OF E-CADHERIN PROTEIN BY IMMUNOHISTOCHEMICAL STAINING IN DIFFERENT PARAFFIN-EMBEDDED SAMPLES OF DYSPLASTIC AND NON-DYSPLASTIC ORIGIN IN A SUBSET OF OUR PATIENTS. SAMPLES WITH DYSPLASIA DISPLAYED REDUCED LEVELS, WHEREAS SAMPLES WITHOUT DYSPLASIA REVEALED NORMAL E-CADHERIN PROTEIN SYNTHESIS. THESE RESULTS SHOW THAT THE E-CADHERIN PROMOTER IS SUBJECTED TO EPIGENETIC CONTROL IN COLORECTAL ULCERATION. OBVIOUSLY, THIS EVENT MAY PLAY AN IMPORTANT ROLE IN THE PROGRESSION FROM CHRONIC INFLAMMATION TO COLORECTAL CANCER. FOR THIS REASON, METHYLATION OF THE CDH1 PROMOTER IS AN ATTRACTIVE NEW BIOMARKER FOR DETECTING ULCERATIVE COLITIS PATIENTS WITH A HIGH RISK FOR DEVELOPING COLORECTAL CANCERS. 2002 5 2019 43 EPIGENETIC CHANGE IN E-CADHERIN AND COX-2 TO PREDICT CHRONIC PERIODONTITIS. BACKGROUND: DNA METHYLATION OF CERTAIN GENES FREQUENTLY OCCURS IN NEOPLASTIC CELLS. ALTHOUGH THE CAUSE REMAINS UNKNOWN, MANY GENES HAVE BEEN IDENTIFIED WITH SUCH ATYPICAL METHYLATION IN NEOPLASTIC CELLS. THE HYPERMETHYLATION OF E-CADHERIN AND CYCLOOXYGENASE 2 (COX-2) IN CHRONIC INFLAMMATION SUCH AS CHRONIC PERIODONTITIS MAY DEMONSTRATE MILD LESION/MUTATION EPIGENETIC LEVEL. THIS STUDY COMPARES THE HYPERMETHYLATION STATUS OF E-CADHERIN AND COX-2 GENES WHICH ARE OFTEN FOUND IN BREAST CANCER PATIENTS WITH THAT IN CHRONIC PERIODONTITIS. METHODS: TOTAL DNA WAS EXTRACTED FROM THE BLOOD SAMPLES OF 108 SYSTEMICALLY HEALTHY NON-PERIODONTITIS SUBJECTS, AND THE GINGIVAL TISSUES AND BLOOD SAMPLES OF 110 CHRONIC PERIODONTITIS PATIENT AS WELL AS NEOPLASTIC TISSUES OF 106 BREAST CANCER PATIENTS. METHYLATION-SPECIFIC PCR FOR E-CADHERIN AND COX-2 WAS PERFORMED ON THESE SAMPLES AND THE PCR PRODUCTS WERE ANALYZED ON 2% AGAROSE GEL. RESULTS: HYPERMETHYLATION OF E-CADHERIN AND COX-2 WAS OBSERVED IN 38% AND 35% OF THE BREAST CANCER SAMPLES, RESPECTIVELY. IN CHRONIC PERIODONTITIS PATIENTS THE DETECTION RATE WAS 25% AND 19% RESPECTIVELY, AND NONE WAS FOUND IN THE SYSTEMICALLY HEALTHY NON-PERIODONTITIS CONTROL SUBJECTS. THE HYPERMETHYLATION STATUS WAS SHOWN TO BE CORRELATED AMONG THE THREE GROUPS WITH STATISTICAL SIGNIFICANCE (P < 0.0001). THE METHYLATION OF CPG ISLANDS IN E-CADHERIN AND COX-2 GENES IN PERIODONTITIS PATIENTS OCCURS MORE FREQUENTLY IN PERIODONTITIS PATIENTS THAN IN THE CONTROL SUBJECTS, BUT OCCURS LESS FREQUENTLY THAN IN THE BREAST CANCER PATIENTS. CONCLUSIONS: THIS SET OF DATA SHOWS THAT THE EPIGENETIC CHANGE IN E-CADHERIN AND CYCLOOXYGENASE-2 IS ASSOCIATED WITH CHRONIC PERIODONTITIS. THE EPIGENETIC CHANGES PRESENTED IN CHRONIC INFLAMMATION PATIENTS MIGHT DEMONSTRATE AN IRREVERSIBLE DESTRUCTION IN THE TISSUES OR ORGANS SIMILAR TO THE EFFECTS OF CANCER. CHRONIC PERIODONTITIS TO SOME EXTENT MIGHT BE ASSOCIATED WITH DNA HYPERMETHYLATION WHICH IS RELATED TO CANCER RISK FACTORS. 2010 6 1805 34 EFFECT OF SMOKING ON THE DNA METHYLATION PATTERN OF THE SOCS1 PROMOTER IN EPITHELIAL CELLS FROM THE SALIVA OF PATIENTS WITH CHRONIC PERIODONTITIS. BACKGROUND: THE AIM OF THE PRESENT STUDY WAS TO EVALUATE THE METHYLATION PATTERN IN THE SUPPRESSOR OF CYTOKINE SIGNALING 1 (SOCS1) GENE IN SMOKERS AND NON-SMOKERS WITH CHRONIC PERIODONTITIS (CP). METHODS: METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) WAS PERFORMED TO DETERMINE THE METHYLATION STATUS OF THE SOCS1 PROMOTER IN 45 SALIVA SAMPLES FROM SMOKERS AND NON-SMOKERS WITH CP. RESULTS: CELLS FROM THE SALIVA OF CP PATIENTS WHO SMOKED WERE 7.08 TIMES MORE LIKELY TO HAVE A METHYLATED SOCS1 PROMOTER THAN CELLS FROM THE SALIVA OF NON-SMOKING PATIENTS. CONCLUSIONS: SOCS1 GENE PROMOTER METHYLATION, WITH ITS POTENTIAL EFFECTS ON THE EXPRESSION OF THIS GENE, SEEMS TO BE A CONSEQUENCE OF EXPOSURE TO TOBACCO AND NOT TO PERIODONTAL DISEASE. FURTHER STUDIES ARE NEEDED TO ELUCIDATE THE RELATIONSHIP BETWEEN THE EPIGENETIC CONTROL OF IMMUNE RESPONSE GENE EXPRESSION, EXPOSURE TO ENVIRONMENTAL FACTORS, AND THE DEVELOPMENT, PROGRESSION, AND PROGNOSIS OF CP. 2019 7 2682 36 EVALUATION OF SERUM LINE-1 HYPOMETHYLATION AS A PROGNOSTIC MARKER FOR HEPATOCELLULAR CARCINOMA. BACKGROUND AND STUDY AIMS: GLOBAL HYPOMETHYLATION IS ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN CANCER. DEVELOPMENT OF HEPATOCELLULAR CARCINOMA (HCC) MUST BE UNDERSTOOD AS A MULTISTEP PROCESS WITH ACCUMULATION OF GENETIC AND EPIGENETIC ALTERATIONS. IN THE LAST DECADES, IN ADDITION TO GENETIC ALTERATIONS, EPIGENETIC CHANGES HAVE BEEN RECOGNIZED AS AN IMPORTANT AND ALTERNATIVE MECHANISM IN TUMOURIGENESIS. WE INVESTIGATED THE CLINICAL IMPLICATIONS OF GLOBAL HYPOMETHYLATION IN THE SERA OF PATIENTS WITH HEPATOCELLULAR CARCINOMA (HCC). PATIENTS AND METHODS: PCR WAS USED TO ASSESS THE METHYLATION STATUS OF LONG INTERSPERSED NUCLEAR ELEMENT TYPE 1 (LINE-1) REPETITIVE SEQUENCES IN GENOMIC DNA DERIVED FROM SERA OF 50 PATIENTS WITH HCC, 20 PATIENTS WITH CIRRHOSIS, 20 PATIENTS WITH CHRONIC HEPATITIS C AND 10 HEALTHY SUBJECTS. RESULTS: SERUM GENOME HYPOMETHYLATION WAS SIGNIFICANTLY INCREASED IN PATIENTS WITH HCC (P<0.001). THE LEVELS OF SERUM LINE-1 HYPOMETHYLATION AT INITIAL PRESENTATION CORRELATED SIGNIFICANTLY WITH TUMOUR SIZE, TUMOUR NUMBER AND ALPHA-FOETOPROTEIN LEVEL. MOREOVER HIGH SERUM LINE-1 HYPOMETHYLATION CORRELATES SIGNIFICANTLY WITH POOR SURVIVAL. CONCLUSION: SERUM LINE-1 HYPOMETHYLATION MAY SERVE AS A PROGNOSTIC MARKER FOR PATIENTS WITH HCC. 2011 8 507 40 ASSOCIATION OF INCREASED DNA METHYLTRANSFERASE EXPRESSION WITH CARCINOGENESIS AND POOR PROGNOSIS IN PANCREATIC DUCTAL ADENOCARCINOMA. INTRODUCTION: EPIGENETIC MODIFICATIONS PLAY AN IMPORTANT ROLE IN MULTISTAGE CARCINOGENESIS. THE ROLE OF THE THREE FUNCTIONAL DNA METHYLTRANSFERASES (DNMTS) IN PANCREATIC CARCINOGENESIS HAS NOT BEEN FULLY UNDERSTOOD. THE MAIN GOAL OF THIS STUDY WAS TO EXAMINE DNMT EXPRESSION IN DIFFERENT STAGES OF PANCREATIC DUCTAL ADENOCARCINOMA (PDAC), AND EVALUATE THEIR PROGNOSTIC SIGNIFICANCE IN PDAC. MATERIALS AND METHODS: A LARGE NUMBER OF PREMALIGNANT AND MALIGNANT PANCREATIC LESIONS WERE OBTAINED BY MANUAL MICRODISSECTION. QUANTITATIVE REAL-TIME RT-PCR WAS USED TO DETECT DNMTS MRNA EXPRESSION. NONPARAMETRIC TEST, LOGRANK TEST AND COX REGRESSION ANALYSIS WERE USED TO EVALUATE THE CLINICAL SIGNIFICANCE OF DNMT EXPRESSION. RESULTS: THE MRNA EXPRESSION OF THE THREE DNMTS INCREASED WITH THE DEVELOPMENT OF PANCREATIC CANCER FROM NORMAL DUCT TO PANCREATIC INTRADUCTAL NEOPLASIA AND FURTHER TO PDAC, AND WERE STATISTICALLY CORRELATED WITH EACH OTHER. EXPRESSION OF THE THREE DNMTS WAS STATISTICALLY CORRELATED WITH TNM STAGING AND HISTORY OF CHRONIC PANCREATITIS. DNMT3A AND DNMT3B, BUT NOT DNMT1 EXPRESSION, WAS STATISTICALLY CORRELATED WITH TUMOUR SIZE. PATIENTS WITH HIGHER LEVELS OF DNMT1, DNMT3A AND/OR DNMT3B EXPRESSION HAD AN OVERALL LOWER SURVIVAL THAN THOSE WITH LOWER LEVELS OF EXPRESSION. UNIVARIATE ANALYSIS SHOWED THAT HIGH EXPRESSION LEVELS OF DNMTS, ALCOHOL CONSUMPTION, TUMOUR DIFFERENTIATION AND TNM STAGING WERE STATISTICALLY SIGNIFICANT RISK FACTORS. MULTIVARIATE ANALYSIS SHOWED THAT HIGH LEVEL OF DNMT3B EXPRESSION AND TUMOUR DIFFERENTIATION WERE STATISTICALLY SIGNIFICANT INDEPENDENT POOR PROGNOSTIC FACTORS. CONCLUSIONS: THESE RESULTS SUGGESTED THAT PANCREATIC CARCINOGENESIS INVOLVES AN INCREASED MRNA EXPRESSION OF THREE DNMTS, AND THEY MAY BECOME VALUABLE DIAGNOSTIC AND PROGNOSTIC MARKERS AS WELL AS POTENTIAL THERAPEUTIC TARGETS FOR PANCREATIC CANCER. 2012 9 5276 43 PROMOTER METHYLATION OF TUMOR-RELATED GENES IN GASTRIC CARCINOGENESIS. ABERRANT PROMOTER METHYLATION AND SUBSEQUENT SILENCING OF CANCER-RELATED GENES HAS BEEN RECOGNIZED AS AN IMPORTANT PATHWAY INVOLVED IN GASTRIC CARCINOGENESIS. IN FACT, SEVERAL FACTORS ARE BELIEVED TO CONTRIBUTE TO ITS INDUCTION IN GASTRIC EPITHELIA, INCLUDING AGING, DIET, CHRONIC INFLAMMATION AND INFECTION OF HELICOBACTER PYLORI (H. PYLORI) AND EPSTEIN-BARR VIRUS (EBV). HOWEVER, THE UNDERLING MECHANISMS ARE NOT COMPLETELY IDENTIFIED, DESPITE THE BELIEF THAT INCREASED EXPRESSION OR ACTIVITY OF DNA METHYLTRANSFERASES (DNMTS), OR DECREASED DEMETHYLATION ACTIVITY MAY CONTRIBUTE TO THE EXCESSIVE METHYLATION. A GREAT NUMBER OF GENES WITH PROMOTER METHYLATION HAVE BEEN OBSERVED IN GASTRIC CANCER (GC), AMONG WHICH P16INK4A (P16), MUT L HOMOLOGUE 1 (MLH1), EPITHELIAL-CADHERIN (E-CADHERIN), RUNT-RELATED TRANSCRIPTION FACTOR 3 (RUNX3), ADENOMATOUS POLYPOSIS COLI (APC), O(6)-METHYLGUANINE-DNA METHYLTRANSFERASE (MGMT), RAS ASSOCIATION DOMAIN FAMILY 1A (RASSF1A) AND DEATH-ASSOCIATED PROTEIN KINASE (DAPK) HAVE BEEN EXTENSIVELY STUDIED. UNLIKE THE DISTINCT METHYLATION CHARACTERIZATION IN SINGLE GENES, METHYLATION ANALYSIS OF MULTIPLE GENES MAY PROVIDE MORE INFORMATION IN RISK PREDICTION, EARLY DETECTION, PROGNOSIS ASSESSMENT AND CHEMOTHERAPY CHOICE FOR GC. SPECIFICALLY, PARTICULAR MONITORING AND SCREENING SHOULD BE PERFORMED ON THOSE OVER 45 YEARS OLD, WITH PRECANCEROUS GASTRIC DISEASE OR INFECTION OF H. PYLORI OR EBV. AS AN ALTERNATIVE TO TUMOR TISSUES, METHYLATION DETECTION IN PATIENT SERA OR GASTRIC WASHES MAY ALSO BE USED IN RISK PREDICTION AND EARLY DETECTION. HOWEVER, WHAT STILL POSES A GREAT CHALLENGE AS WELL AS A PUZZLE IS THE DETERMINATION OF THE VERY GENES THAT SHOULD BE USED IN METHYLATION ANALYSIS. BECAUSE EPIGENETIC ALTERATIONS ARE NORMALLY REVERSIBLE, DRUGS OR CHEMICAL COMPOUNDS WITH DEMETHYLATING ACTIVITY, SUCH AS 5-AZA-2'-DEOXYCYTIDINE (5-AZA-DC) COULD BE USED IN THE TREATMENT OF PATIENTS WITH MULTIPLE GENE METHYLATION. IN VIEW OF THE ADVERSE EFFECTS OF 5-AZA-DC, DNMT-TARGETED STRATEGY HAS BEEN PROPOSED AND MAY PROVE TO BE MORE EFFECTIVE THAN DEMETHYLATING AGENTS. 2012 10 414 46 ANALYSIS OF PROMOTER METHYLATION IN STOOL: A NOVEL METHOD FOR THE DETECTION OF COLORECTAL CANCER. BACKGROUND & AIMS: DETECTION OF TUMOR-DERIVED DNA ALTERATIONS IN STOOL IS AN INTRIGUING NEW APPROACH WITH HIGH POTENTIAL FOR THE NONINVASIVE DETECTION OF COLORECTAL CANCER (CRC). BECAUSE OF HETEROGENEITY OF TUMORS, USUALLY MULTIPLE MARKERS DISTRIBUTED THROUGHOUT THE HUMAN GENOME NEED TO BE ANALYZED. THIS IS LABOR INTENSIVE AND DOES NOT ALLOW FOR HIGH THROUGH-PUT SCREENING. THEREFORE, MARKERS WITH HIGH SENSITIVITY AND GOOD SPECIFICITY ARE NEEDED. WE EXPLORED THE POTENTIAL OF A SINGLE EPIGENETIC MARKER IN COMPARISON WITH FECAL OCCULT BLOOD TESTING (FOBT) FOR THE DISCRIMINATION OF PATIENTS WITH CRCS AND ADENOMAS FROM THOSE WITHOUT. METHODS: METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (PCR) WAS PERFORMED TO ANALYZE HYPERMETHYLATED IN CANCER 1 (HIC1) PROMOTER METHYLATION STATUS IN A BLINDED FASHION IN STOOL SAMPLES FROM 26 PATIENTS WITH CRC, 13 WITH ADENOMA > OR =1 CM, 9 WITH HYPERPLASTIC POLYPS, 9 WITH CHRONIC INFLAMMATORY BOWEL DISEASE, AND 32 WITH ENDOSCOPICALLY NORMAL COLON. RESULTS: NINETY-SEVEN PERCENT OF THE STOOL SAMPLES CONTAINED AMPLIFIABLE DNA. FORTY-TWO PERCENT OF THE SAMPLES FROM PATIENTS WITH CRC AND 31% OF THE SAMPLES FROM PATIENTS WITH COLORECTAL ADENOMA > OR =1 CM WERE POSITIVE FOR HIC1 PROMOTER METHYLATION. NO METHYLATED HIC1 PROMOTER DNA WAS DETECTED IN THE FECAL DNA FROM PATIENTS WITH ENDOSCOPICALLY NORMAL COLON OR HYPERPLASTIC POLYPS. CONCLUSIONS: THE EPIGENETIC MARKER HIC1 PROMOTER METHYLATION CARRIES HIGH POTENTIAL FOR THE REMOTE DETECTION OF CRCS. WE POSTULATE THAT A PANEL OF MERELY A FEW GENETIC AND EPIGENETIC MARKERS WILL BE REQUIRED FOR THE HIGHLY SENSITIVE AND SPECIFIC DETECTION OF CRCS AND ADENOMAS IN FECAL SAMPLES FROM AFFECTED PATIENTS. 2005 11 3897 38 LARGE-SCALE ANALYSIS OF THE GENETIC AND EPIGENETIC ALTERATIONS IN HEPATOCELLULAR CARCINOMA FROM SOUTHEAST CHINA. OUR KNOWLEDGE ABOUT MOLECULAR ALTERATIONS DURING HEPATOCARCINOGENESIS IS STILL FRAGMENTARY, DUE TO LACK OF COMPREHENSIVE GENETIC AND EPIGENETIC ANALYSES IN THE SAME SET OF HEPATOCELLULAR CARCINOMAS (HCCS). IN THIS STUDY, WE CONDUCTED A LARGE-SCALE ANALYSIS, INCLUDING MUTATION SCREENING IN 50 GENES AND METHYLATION ASSAYS IN THREE GENES IN 54 PAIRS OF HCCS AND THEIR NEIGHBORING NON-CANCEROUS TISSUES. ALL SAMPLES WERE COLLECTED FROM THE RESIDENTS IN SOUTHEAST CHINA. WE FOUND HBV INFECTION AND CHRONIC HEPATITIS/CIRRHOSIS IN 83.3% AND 98.1% OF THE CASES, RESPECTIVELY. MUTATIONS WERE IDENTIFIED IN 18 OUT OF 54 (33.3%) SAMPLES, WITH P53 ALTERATIONS IN 14 CASES AND BETA-CATENIN MUTATIONS IN FOUR TUMORS. NO MUTATIONS WERE IDENTIFIED IN THE NEIGHBORING TISSUES. INTERESTINGLY, 9 OUT OF 14 (64.3%) TUMORS CARRYING P53 MUTATIONS DISPLAYED SUBSTITUTION OF SERINE BY ARGININE AT CODON 249, A CHARACTERISTIC CHANGE BELIEVED TO BE INDUCED BY AFLATOXIN-B1. FURTHERMORE, P53 MUTATION WAS SIGNIFICANTLY ASSOCIATED WITH SHORTER RECURRENCE-FREE SURVIVAL (P=0.004). THE RESULTS ALSO REVEALED ABERRANT METHYLATION IN TWO OR MORE GENES IN AS HIGH AS 90% OF TUMORS AND 40% OF ADJACENT TISSUES. THE FREQUENCY OF RASSF1A HYPERMETHYLATION WAS MUCH HIGHER THAN THAT OF P16INK4A AND HAI2 IN BOTH HCC AND NEIGHBORING TISSUES, INDICATING THAT DEREGULATION OF RASSF1A MAY PRECEDE THE OTHER TWO GENES. THESE DATA SUGGEST THAT ABERRANT METHYLATION OCCURS BEFORE MUTATION AND IS AN EARLY EVENT IN THE DEVELOPMENT OF THIS SET OF HCC. OUR FINDINGS HIGHLIGHT P53 AS A PROGNOSTIC FACTOR OF HCC AND RASSF1A AS A POTENTIAL TARGET IN PREVENTING MALIGNANT TRANSFORMATION OF HEPATOCYTES. 2008 12 59 36 A GENOME-WIDE SCREEN IDENTIFIES FREQUENTLY METHYLATED GENES IN HAEMATOLOGICAL AND EPITHELIAL CANCERS. BACKGROUND: GENETIC AS WELL AS EPIGENETIC ALTERATIONS ARE A HALLMARK OF BOTH EPITHELIAL AND HAEMATOLOGICAL MALIGNANCIES. HIGH THROUGHPUT SCREENS ARE REQUIRED TO IDENTIFY EPIGENETIC MARKERS THAT CAN BE USEFUL FOR DIAGNOSTIC AND PROGNOSTIC PURPOSES ACROSS MALIGNANCIES. RESULTS: HERE WE REPORT FOR THE FIRST TIME THE USE OF THE MIRA ASSAY (METHYLATED CPG ISLAND RECOVERY ASSAY) IN COMBINATION WITH GENOME-WIDE CPG ISLAND ARRAYS TO IDENTIFY EPIGENETIC MOLECULAR MARKERS IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKEMIA (ALL) ON A GENOME-WIDE SCALE. WE IDENTIFIED 30 GENES DEMONSTRATING METHYLATION FREQUENCIES OF > OR =25% IN CHILDHOOD ALL, NINE GENES SHOWED SIGNIFICANTLY DIFFERENT METHYLATION FREQUENCIES IN B VS T-ALL. FOR MAJORITY OF THE GENES EXPRESSION COULD BE RESTORED IN METHYLATED LEUKEMIA LINES AFTER TREATMENT WITH 5-AZADC. FORTY-FOUR PERCENT OF THE GENES REPRESENT TARGETS OF THE POLYCOMB COMPLEX. IN CHRONIC MYELOID LEUKEMIA (CML) TWO OF THE GENES, (TFAP2A AND EBF2), DEMONSTRATED INCREASED METHYLATION IN BLAST CRISIS COMPARED TO CHRONIC PHASE (P < 0.05). FURTHERMORE HYPERMETHYLATION OF AN AUTOPHAGY RELATED GENE ATG16L2 WAS ASSOCIATED WITH POORER PROGNOSIS IN TERMS OF MOLECULAR RESPONSE TO IMATINIB TREATMENT. LASTLY WE DEMONSTRATED THAT TEN OF THESE GENES WERE ALSO FREQUENTLY METHYLATED IN COMMON EPITHELIAL CANCERS. CONCLUSION: IN SUMMARY WE HAVE IDENTIFIED A LARGE NUMBER OF GENES SHOWING FREQUENT METHYLATION IN CHILDHOOD ALL, METHYLATION STATUS OF TWO OF THESE GENES IS ASSOCIATED WITH ADVANCED DISEASE IN CML AND METHYLATION STATUS OF ANOTHER GENE IS ASSOCIATED WITH PROGNOSIS. IN ADDITION A SUBSET OF THESE GENES MAY ACT AS EPIGENETIC MARKERS ACROSS HEMATOLOGICAL MALIGNANCIES AS WELL AS COMMON EPITHELIAL CANCERS. 2010 13 6692 41 VARIABLE DNA METHYLATION PATTERNS ASSOCIATED WITH PROGRESSION OF DISEASE IN HEPATOCELLULAR CARCINOMAS. HEPATOCELLULAR CARCINOMA (HCC) MOST COMMONLY ARISES FROM CHRONIC INFLAMMATION DUE TO VIRAL INFECTION, AS A RESULT OF GENETIC AND EPIGENETIC ABNORMALITIES. A GLOBAL PICTURE OF EPIGENETIC CHANGES IN HCC IS LACKING. WE USED METHYLATED CPG ISLAND AMPLIFICATION MICROARRAYS (MCAMS) TO STUDY 6458 CPG ISLANDS IN HCC AND ADJACENT PRENEOPLASTIC TISSUES [CHRONIC HEPATITIS (CH) OR LIVER CIRRHOSIS (LC)] IN COMPARISON WITH NORMAL LIVER TISSUES WHERE NEITHER VIRAL INFECTION NOR HEPATITIS HAS EXISTED. MCAM IDENTIFIED 719 (11%) PROMINENT GENES OF HYPERMETHYLATION IN HCCS. HCCS ARISING FROM LC HAD SIGNIFICANTLY MORE METHYLATION THAN THOSE ARISING FROM CH (1249 GENES OR 19% VERSUS 444 GENES OR 7%, P < 0.05). THERE WERE FOUR PATTERNS OF ABERRANT METHYLATION: TYPE I (4%, E.G. MATRIX METALLOPROTEINASE 14) SHOWS A SUBSTANTIALLY HIGH METHYLATION LEVEL IN ADJACENT TISSUE AND DOES NOT INCREASE FURTHER IN CANCER. TYPE II (55%, E.G. RASSF1A) SHOWS PROGRESSIVELY INCREASING METHYLATION FROM ADJACENT TISSUE TO HCC. TYPE III (4%, E.G. GNA14) SHOWS DECREASED METHYLATION IN ADJACENT TISSUE BUT EITHER SIMILAR OR INCREASED METHYLATION IN HCC. TYPE IV (37%, E.G. CDKN2A) SHOWS LOW LEVELS OF METHYLATION IN NORMAL TISSUE AND ADJACENT TISSUE BUT HIGH LEVELS IN HCC. THESE DNA METHYLATION CHANGES WERE CONFIRMED BY QUANTITATIVE PYROSEQUENCING METHYLATION ANALYSIS IN REPRESENTATIVE 24 GENES AND WERE ANALYZED FOR CORRELATION WITH CLINICOPATHOLOGICAL PARAMETERS IN 38 PATIENTS. INTRIGUINGLY, METHYLATION IN THE TYPE IV GENES IS CHARACTERISTIC OF MODERATELY/POORLY DIFFERENTIATED CANCER. OUR GLOBAL EPIGENOME ANALYSIS REVEALS DISTINCT PATTERNS OF METHYLATION THAT ARE PROBABLY TO REPRESENT DIFFERENT PATHOPHYSIOLOGIC PROCESSES IN HCCS. 2008 14 3588 43 IMPACT OF TP53 GENE PROMOTER METHYLATION ON CHRONIC LYMPHOCYTIC LEUKEMIA PATHOGENESIS AND PROGRESSION. BACKGROUND: CHRONIC LYMPHOCYTIC LEUKEMIA (CLL) IS A MALIGNANT LYMPHOID DISORDER THAT RESULTS FROM THE OVERGROWTH OF MATURE-LOOKING LYMPHOID CELLS IN THE BLOOD AND LYMPHATIC TISSUE. VARIOUS CLINICAL PRESENTATIONS HAVE BEEN ATTRIBUTED TO THE DISEASE AS A RESULT OF THE DIFFERENT UNDERLYING GENETIC AND EPIGENETIC ALTERATIONS. THE CURRENT STUDY HAS BEEN INITIATED TO STUDY THE ROLE OF AN EPIGENETIC ALTERATION AFFECTING THE PROMOTER OF THE TP53GENE ON CLL PATHOGENESIS AND PROGRESSION. METHODS: THE CURRENT STUDY INVOLVED 54 NEWLY DIAGNOSED PATIENTS PRESENTING WITH CLL AS WELL AS 30 NORMAL INDIVIDUALS AS CONTROLS. AFTER OBTAINING VERBAL CONSENT, DATA COLLECTION WAS DONE AND THE BLOOD COLLECTED FROM ALL ENROLLED INDIVIDUALS FOR HEMATOLOGICAL INVESTIGATIONS AS WELL AS FOR MOLECULAR CATEGORIZATION OF TP53 METHYLATION STATUS. METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION (MS-PCR) TECHNIQUE WAS USED TO DEFINE THE METHYLATION STATUS OF THE TP53 GENE PROMOTER THAT ENCOMPASSES DNA EXTRACTION, BISULFITE CONVERSION, CONVENTIONAL PCR AMPLIFICATION, RUNNING ON AGAROSE GEL AND DOCUMENTATION. FINALLY, STATISTICAL ANALYSIS WAS DONE TO ASSESS ANY CORRELATION OF THE TP53 EPIGENETIC ALTERATION TO THE DISEASE ETIOLOGY AND THE PROGRESSION. RESULTS: IN THE CURRENT STUDY, ALL CONTROLS AND 42 OF 54 PATIENTS SHOW UNMETHYLATED TP53 GENE PROMOTER; ON THE OTHER HAND, THE METHYLATED PROMOTER WAS DETECTED AMONG 12 PATIENTS WITH A P-VALUE OF 0.001. TP53 GENE PROMOTER METHYLATION SIGNIFICANTLY LINKED TO REDUCED PLATELET COUNT (P-VALUE OF 0.047) AND ADVANCED STAGE AT PRESENTATION (P-VALUE OF 0.076). NO SIGNIFICANT DIFFERENCES WERE SEEN AMONG BOTH METHYLATED AND UNMETHYLATED TP53 PROMOTERS IN RELATION TO THE AGE OF THE AFFECTED INDIVIDUALS, TOTAL WHITE BLOOD CELL COUNTS AND HEMOGLOBIN LEVEL OF THE AFFECTED INDIVIDUALS. CONCLUSION: THE CURRENT STUDY REVEALED A SIGNIFICANT CORRELATION OF TP53 GENE PROMOTER METHYLATION TO CHRONIC LYMPHOCYTIC LEUKEMIA PATHOGENESIS AND LOWER PLATELET COUNTS. 2019 15 1582 37 DNA METHYLATION PROFILES IN PRECANCEROUS TISSUE AND CANCERS: CARCINOGENETIC RISK ESTIMATION AND PROGNOSTICATION BASED ON DNA METHYLATION STATUS. ALTERATIONS IN DNA METHYLATION, WHICH ARE ASSOCIATED WITH DNA METHYLTRANSFERASE ABNORMALITIES AND RESULT IN SILENCING OF TUMOR-RELATED GENES AND CHROMOSOMAL INSTABILITY, ARE INVOLVED EVEN IN PRECANCEROUS CHANGES IN VARIOUS ORGANS. DNA METHYLATION ALTERATIONS ALSO ACCOUNT FOR THE HISTOLOGICAL HETEROGENEITY AND CLINICOPATHOLOGICAL DIVERSITY OF HUMAN CANCERS. THEREFORE, WE HAVE ANALYZED DNA METHYLATION ON A GENOME-WIDE SCALE IN CLINICAL TISSUE SAMPLES. OUR APPROACH USING THE BACTERIAL ARTIFICIAL CHROMOSOME ARRAY-BASED METHYLATED CPG ISLAND AMPLIFICATION METHOD HAS REVEALED THAT DNA METHYLATION ALTERATIONS CORRELATED WITH THE FUTURE DEVELOPMENT OF MORE MALIGNANT CANCERS ARE ALREADY ACCUMULATED AT THE PRECANCEROUS STAGE IN THE KIDNEY, LIVER AND URINARY TRACT. DNA METHYLATION PROFILES AT PRECANCEROUS STAGES ARE BASICALLY INHERITED BY THE CORRESPONDING CANCERS DEVELOPING IN INDIVIDUAL PATIENTS. SUCH DNA METHYLATION ALTERATIONS MAY CONFER VULNERABILITY TO FURTHER GENETIC AND EPIGENETIC ALTERATIONS, GENERATE MORE MALIGNANT CANCERS, AND THUS DETERMINE PATIENT OUTCOME. ON THE BASIS OF BACTERIAL ARTIFICIAL CHROMOSOME ARRAY-BASED METHYLATED CPG ISLAND AMPLIFICATION DATA, INDICATORS FOR CARCINOGENETIC RISK ESTIMATION HAVE BEEN ESTABLISHED USING LIVER TISSUE SPECIMENS FROM PATIENTS WITH HEPATITIS VIRUS INFECTION, CHRONIC HEPATITIS AND LIVER CIRRHOSIS OR HISTOLOGICALLY NORMAL UROTHELIA, AND FOR PROGNOSTICATION USING BIOPSY OR SURGICALLY RESECTED SPECIMENS FROM PATIENTS WITH RENAL CELL CARCINOMA, HEPATOCELLULAR CARCINOMA AND UROTHELIAL CARCINOMA. SUCH GENOME-WIDE DNA METHYLATION PROFILING HAS NOW FIRMLY ESTABLISHED THE CLINICAL RELEVANCE OF TRANSLATIONAL EPIGENETICS. 2010 16 6820 40 [GASTRIC CARCINOMA AND CHRONIC GASTRITIS: EPIGENETIC REGULATION OF CDH1 (E-CADHERIN), CDKN2A (P16INK4A), PTGS2 (COX-2) AND EGFR GENES THROUGH METHYLATION]. THE GENETIC AND EPIGENETIC ALTERATIONS ARE BEING STUDIED AS ONE OF THE CAUSES OF GASTRIC CANCER (GC) PROGRESSION AND DEVELOPMENT. DNA METHYLATION IS AN EPIGENETIC ALTERATION WHICH LEADS TO SUPPRESSOR GENE SILENCING AND PROTO-ONCOGENE ACTIVATION, PLAYING AN IMPORTANT ROLE IN CARCINOGENESIS. THE HISTOLOGICAL TYPES OF GASTRIC CARCINOMA HAVE DIFFERENT GENETIC PATHS AND THE KNOWLEDGE OF THE MOLECULAR BASES OF TUMORAL PROGRESSION LEADS TO DIAGNOSTIC ACCURACY AND ATTEMPTED THERAPY. CDH1 (E-CADHERIN) AND CDKN2A (P16(INK4A)) GENES ARE THOUGHT TO BE TUMORAL SUPPRESSOR GENES AND PTGS2 (COX-2) AND GENES ARE INVOLVED IN TUMOUR REGULATION AND GROWTH. IN ONE HAND, GENE SILENCING AS AN EPIGENETIC PHENOMENON, AND IN THE OTHER HAND, GENE EXPRESSION ENHANCEMENT DUE TO POSSIBLE DEMETHYLATION, SIMULTANEOUSLY, CAN FACILITATE CARCINOGENESIS AND TUMORAL PROGRESSION. OUR AIM WAS TO RELATE CDH1, P16(INK4A), COX-2 AND EGFR GENES DNA METHYLATION WITH THE SEVERAL HISTOLOGICAL TYPES OF GASTRIC CARCINOMA AND CHRONIC GASTRITIS. WE STUDIED 55 FORMALIN FIXED PARAFFIN EMBEDDED GASTRIC BIOPSIES: 35 WERE GC SPECIMENS (12 DIFFUSE TYPE, 15 INTESTINAL TYPE AND 8 INDETERMINATE TYPE, ACCORDING TO LAUREN'S CLASSIFICATION) AND 20 SAMPLES HAD CHRONIC GASTRITIS (CG). THE DNA WAS TREATED WITH SODIUM BISULFITE AFTER EXTRACTION AND THEN PERFORMED METHYLATION SPECIFIC PCR (MSP). STATISTICAL ANALYSIS WAS BASED ON CHI-SQUARE TEST AND EXACT FISHER'S TEST. CPG ISLAND METHYLATION WAS DETECTED IN 94% OF THE GC SAMPLES FOR CDH1, 91% FOR COX-2, 80% FOR P16(INK4A) AND NO METHYLATION WAS DETECTED IN EGFR GENE (0%). IN CG, CPG ISLAND METHYLATION WAS FOUND IN 100% FOR CDH1 AND COX-2 GENES, 90% FOR P16(INK4A) AND 20% FOR EGFR. THESE RESULTS REVEAL SIGNIFICANT DIFFERENCES IN EGFR GENE METHYLATION DISTINGUISHING GC FROM CG (P < 0, 01), SUGGESTING THAT GENE DEMETHYLATION LEADS TO MALIGNANT TRANSFORMATION AND FAVOURS THE USE OF TYROSINE-KINASE INHIBITORS IN ITS TREATMENT. GENES COX2 E P16INK4A LOWER METHYLATION IN INTESTINAL AND DIFFUSE TYPES OF GC, FAVOURS THEIR DIFFERENT ROLE IN RESPECTIVE HISTOGENESIS. 2010 17 3686 36 INFLAMMATION-RELATED ABERRANT PATTERNS OF DNA METHYLATION: DETECTION AND ROLE IN EPIGENETIC DEREGULATION OF CANCER CELL TRANSCRIPTOME. IT IS NOW APPARENT THAT EPIGENETIC ABNORMALITIES, IN PARTICULAR ALTERED DNA METHYLATION, PLAY A CRUCIAL ROLE IN THE DEVELOPMENT AND PROGRESSION OF HUMAN CANCERS. DNA HYPERMETHYLATION AT PROMOTER CPG ISLANDS IS NOW RECOGNIZED AS A THIRD MECHANISM BY WHICH INACTIVATION OF TUMOR SUPPRESSOR GENES OCCURS. ABERRANT CPG ISLAND HYPERMETHYLATION IS ALSO FREQUENTLY OBSERVED IN CHRONIC INFLAMMATION AND PRECANCEROUS LESIONS, WHICH SUGGESTS THAT IT IS AN EARLY EVENT IN TUMORIGENESIS THAT COULD SERVE AS A USEFUL TUMOR MARKER. A VARIETY OF SCREENING TECHNIQUES HAVE BEEN DEVELOPED FOR GENOME-WIDE SCREENING OF METHYLATION STATUS. OF THOSE, TRANSCRIPTOME ANALYSIS COUPLED WITH PHARMACOLOGICAL UNMASKING HAS EMERGED AS A POWERFUL TOOL FOR REVEALING DNA METHYLATION PATTERNS IN CANCER CELLS AND IDENTIFYING NEW TUMOR MARKER CANDIDATES. 2009 18 3646 35 INCREASED PROTEIN EXPRESSION OF DNA METHYLTRANSFERASE (DNMT) 1 IS SIGNIFICANTLY CORRELATED WITH THE MALIGNANT POTENTIAL AND POOR PROGNOSIS OF HUMAN HEPATOCELLULAR CARCINOMAS. ALTERATION OF DNA METHYLATION IS ONE OF THE MOST CONSISTENT EPIGENETIC CHANGES IN HUMAN CANCERS. DNA METHYLTRANSFERASE (DNMT) 1 IS A MAJOR ENZYME INVOLVED IN ESTABLISHING GENOMIC METHYLATION PATTERNS. MOST OF THE STUDIES CONCERNING DNMT1 EXPRESSION IN HUMAN CANCERS HAVE BEEN PERFORMED ONLY AT THE MRNA LEVEL. TO DIRECTLY EXAMINE DNMT1 PROTEIN EXPRESSION LEVELS DURING HUMAN HEPATOCARCINOGENESIS, 16 HISTOLOGICALLY NORMAL LIVER TISSUES, 51 NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS, WHICH ARE CONSIDERED TO BE PRECANCEROUS CONDITIONS, AND 53 HEPATOCELLULAR CARCINOMAS (HCCS) WERE SUBJECTED TO IMMUNOHISTOCHEMIC EXAMINATION. IF MORE THAN 20% OF THE CELLS EXHIBITED NUCLEAR DNMT1 STAINING, THE TISSUE SAMPLE WAS CONSIDERED TO BE DNMT1-POSITIVE. DNMT1 IMMUNOREACTIVITY WAS OBSERVED IN 23 (43%) OF THE HCCS, BUT IN NONE (0%) OF THE HISTOLOGICALLY NORMAL LIVER OR NONCANCEROUS LIVER TISSUES EXHIBITING CHRONIC HEPATITIS OR CIRRHOSIS. THE INCIDENCE OF INCREASED DNMT1 PROTEIN EXPRESSION IN HCCS CORRELATED SIGNIFICANTLY WITH POOR TUMOR DIFFERENTIATION (P = 0.0006) AND PORTAL VEIN INVOLVEMENT (P = 0.0002). MOREOVER, THE RECURRENCE-FREE (P = 0.0001) AND OVERALL (P < 0.0001) SURVIVAL RATES OF PATIENTS WITH HCCS EXHIBITING INCREASED DNMT1 PROTEIN EXPRESSION WERE SIGNIFICANTLY LOWER THAN THOSE OF PATIENTS WITH HCCS THAT DID NOT EXHIBIT INCREASED EXPRESSION. INCREASED DNMT1 PROTEIN EXPRESSION MAY PLAY A CRITICAL ROLE IN THE MALIGNANT PROGRESSION OF HCCS AND BE A BIOLOGIC PREDICTOR OF BOTH HCC RECURRENCE AND A POOR PROGNOSIS IN HCC PATIENTS. 2003 19 2766 41 EXPRESSION, POLYMORPHISM AND METHYLATION PATTERN OF INTERLEUKIN-6 IN PERIODONTAL TISSUES. PERIODONTITIS IS CONSIDERED AN INFLAMMATORY DISORDER OF BACTERIAL ETIOLOGY THAT RESULTS IN PERIODONTAL TISSUE DESTRUCTION, AS A RESULT OF COMPLEX INTERACTIONS BETWEEN PERIODONTAL PATHOGENS, HOST AND IMMUNE RESPONSE. GENETIC AND EPIGENETIC MECHANISMS MAY MODULATE THE INDIVIDUAL RESPONSE SINCE IT IS ABLE TO INFLUENCE THE GENE EXPRESSION. THE AIM OF THIS STUDY WAS TO EVALUATE THE IMPACT OF -174 G/C POLYMORPHISM AND THE METHYLATION STATUS OF THE PROMOTER REGION OF IL-6 GENE ON THE EXPRESSION OF IL-6 IN GINGIVAL SAMPLES FROM INDIVIDUALS WITH CHRONIC PERIODONTITIS. GINGIVAL BIOPSIES WERE COLLECTED FROM 21 PATIENTS WITH CHRONIC PERIODONTITIS AND 21 CONTROLS. HISTOLOGIC SECTIONS STAINED BY HEMATOXYLIN-EOSIN WERE USED FOR HISTOPATHOLOGICAL EVALUATION. THE IL-6 GENE EXPRESSION WAS ASSESSED BY QUANTITATIVE REAL-TIME PCR. THE POLYMORPHISM IL-6 -174 C/G WAS STUDIED BY POLYMERASE CHAIN REACTION (PCR) AMPLIFICATION AND RESTRICTION ENDONUCLEASE DIGESTION (HSPII). METHYLATION-SPECIFIC POLYMERASE CHAIN REACTION WAS USED TO VERIFY THE DNA METHYLATION PATTERN. THE NUMBER OF INFLAMMATORY CELLS IN TISSUE FRAGMENTS FROM INDIVIDUALS WITH CHRONIC PERIODONTITIS WAS HIGHER THAN IN THE CONTROL GROUP AND THE INFLAMMATORY INFILTRATE WAS PREDOMINANTLY MONONUCLEAR. THE EXPRESSION OF IL-6 WAS HIGHER IN THE GROUP WITH PERIODONTITIS. IN POLYMORPHISM ASSAY, NO STATISTICAL DIFFERENCE IN THE DISTRIBUTION OF GENOTYPES AND ALLELES IN BOTH GROUPS WERE OBSERVED. THE MOST OF SAMPLES WERE PARTIALLY METHYLATED. NO DIFFERENCE WAS OBSERVED IN METHYLATION PATTERN FROM TWO DIFFERENT REGIONS OF THE IL-6 GENE AMONG GROUPS. THE HIGH EXPRESSION OF IL-6 IS AN IMPORTANT FACTOR RELATED TO CHRONIC PERIODONTITIS, BUT WAS NOT ASSOCIATED WITH METHYLATION STATUS OR THE -174 (G/C) GENETIC POLYMORPHISM, SUGGESTING THAT OTHER MECHANISMS ARE INVOLVED IN THIS GENE TRANSCRIPTION REGULATION. 2013 20 5706 38 SINGLE-MOLECULE QUANTIFICATION OF 5-HYDROXYMETHYLCYTOSINE FOR DIAGNOSIS OF BLOOD AND COLON CANCERS. BACKGROUND: THE DNA MODIFICATION 5-HYDROXYMETHYLCYTOSINE (5HMC) IS NOW REFERRED TO AS THE SIXTH BASE OF DNA WITH EVIDENCE OF TISSUE-SPECIFIC PATTERNS AND CORRELATION WITH GENE REGULATION AND EXPRESSION. THIS EPIGENETIC MARK WAS RECENTLY REPORTED AS A POTENTIAL BIOMARKER FOR MULTIPLE TYPES OF CANCER, BUT ITS APPLICATION IN THE CLINIC IS LIMITED BY THE UTILITY OF RECENT 5HMC QUANTIFICATION ASSAYS. WE USE A RECENTLY DEVELOPED, ULTRA-SENSITIVE, FLUORESCENCE-BASED SINGLE-MOLECULE METHOD FOR GLOBAL QUANTIFICATION OF 5HMC IN GENOMIC DNA. THE HIGH SENSITIVITY OF THE METHOD GIVES ACCESS TO PRECISE QUANTIFICATION OF EXTREMELY LOW 5HMC LEVELS COMMON IN MANY CANCERS. METHODS: WE ASSESSED 5HMC LEVELS IN DNA EXTRACTED FROM A SET OF COLON AND BLOOD CANCER SAMPLES AND COMPARED 5HMC LEVELS WITH HEALTHY CONTROLS, IN A SINGLE-MOLECULE APPROACH. RESULTS: USING OUR METHOD, WE OBSERVED A SIGNIFICANTLY REDUCED LEVEL OF 5HMC IN BLOOD AND COLON CANCERS AND COULD DISTINGUISH BETWEEN COLON TUMOR AND COLON TISSUE ADJACENT TO THE TUMOR BASED ON THE GLOBAL LEVELS OF THIS MOLECULAR BIOMARKER. CONCLUSIONS: SINGLE-MOLECULE DETECTION OF 5HMC ALLOWS DISTINGUISHING BETWEEN MALIGNANT AND HEALTHY TISSUE IN CLINICALLY RELEVANT AND ACCESSIBLE TISSUE SUCH AS BLOOD AND COLON. THE PRESENTED METHOD OUTPERFORMS CURRENT COMMERCIALLY AVAILABLE QUANTIFICATION KITS AND MAY POTENTIALLY BE DEVELOPED INTO A WIDELY USED, 5HMC QUANTIFICATION ASSAY FOR RESEARCH AND CLINICAL DIAGNOSTICS. FURTHERMORE, USING THIS METHOD, WE CONFIRM THAT 5HMC IS A GOOD MOLECULAR BIOMARKER FOR DIAGNOSING COLON AND VARIOUS TYPES OF BLOOD CANCER. 2017